1. Field of the Invention
The present invention relates to a battery holding method and structure, and particularly to a battery holding method and structure applied to such appliances as cameras or the like.
2. Description of the Related Art
In these years, downsizing of digital cameras has been promoted, and accordingly the battery downsizing and reduction in required number of batteries become critical factors for commercialization. On the other hand, there exists strong market demand for longer service life of batteries, and hence the power saving performance and the reduced contact resistance are now essential challenge in developing commercial products. In relation to the battery holding method and structure, Japanese Utility Model Publication No. 63-28523 and Japanese Patent Application Publication 1-260756 disclose battery holding devices which fix the batteries without play.
However, the structures proposed in the above publications cannot be applied to a battery housing unit having a bottomed tubular battery chamber into which the battery is dropped along the lengthwise direction of the chamber. In a type of battery holder in which the battery is inserted along the lengthwise direction of the holder, conventionally only the forces exerted by the energized terminal clamps abutting to the top and bottom ends of the battery hold the battery. The tolerance for the battery outer diameter is large (for example, 14±0.5 mm in diameter for the size AA battery according to Japanese Industrial Standards), and hence a clearance is usually provided to such a battery chamber (a battery case). Accordingly, when the conventional method is applied in which only the end terminal clamps hold the battery, there occurs a problem that the battery moves within an extent of clearance between the battery and the inner wall of the battery chamber, rotates on the lengthwise axis thereof, or the like, and hence the contact points between the battery and the terminals are varied to make the relevant contact resistance unstable.